Telephone-transmitter.



No. 757.799. PATENTED APR. 19, 1904.

W. L. WILHELM.

TELEPHONE TRANSMITTER.

APPLICATION FILED JAN. 2s, 1902.

Willi/'wwf mi Nanms Farms co. vnoiauwo., WASHINGTON o. L.

No. 757,799. PATENTED APR. 19,' 1904.

u W. L. WILHELM.

TELEPHONE TRANSI5/{1'1"1`ER.v

APPLICATION FILED JAN. 23, 1902. no nonni.. z SHEETS-snm z.

Jlvc afs.

i UNITED. STATESA Patented April 19, 1904.

PATENT OFFICE.

VALTER L. VILHELM, OF BUFFALO, NEW YORK, ASSIGNOR TO WILHELM TELEPHONEMANUFACTURING COMPANY, OF BUFFALO, NEW YORK.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 757,799, dated April19, 1904. i Application led January 23, 1902.l Serial No. 90,895.(No'model.)

To ZZ- whom itjnrty concern,-

Be it known that I, I/VALTER L. W'ILHELM, a citizen of the UnitedStates, residing at Buffalo, in the county of Erie and State of NewYork, have invented new and-useful Improvements inTelephone-Transmitters, of which the following is a specification.

This invention relates to a telephone transmitter or microphone of thatkind wherein a plurality ot' diaphragms are arranged parallel with eachother andbranchtubes or passages are provided leading from a singlemouthpiece to the' diaphragms, so as to direct the sound-waves enteringthe mouthpiece simultaneously against the exposed surfaces of thediaphragms.

The object of the invention is t0 provide a simple, desirable, andattractive mounting for the transmitter or microphone proper which willinclose and protect the microphone and which will permit the readyremoval of the microphone for repairs, alterations, or for Aotherreason.

\ In the accompanying drawings, consisting of two sheets, Figure l isavertical sectional elevation of a telephone-transmitter embodying myinvention. Fig. 2 is a vertical section through the branch-tube holderJfor the microphone detached. Fig. 3 is a front elevation of the'branch-tubeholder. Fig. 4 is a plan view of the microphone-containingframe and branch-tube holder. Fig. 5 is an inner or rear end elevationoi' the branch-tube holder detached. Fig. 6 is a plan view of themicrophone-containing frame detached. Fig.`7 is an enlarged sideelevation of the inclosing casing. Fig. 8' is an enlarged horizontalsection, partly inplan, through the microphone-containing frame. Fig. 9is an enlarged end elevation of the microphone-containing frame. Fig. 10is a side elevation of a branched-tube holder and containing-frame of aslightly-different form. Fig. 1l is anenlarged section through one ofthe binding-posts on the line 11 11,-Fig.10.

Like letters of reference refer tolike parts in the several figures.

A represents the front portion of the usual.

carrying or supporting arm for the transmitter. This arm is provided atits front end with an enlargement a', to which is secured a`substantially spherical casing for inclosing and supporting thetransmitter or microphone. This incloslng casing 1s preferablyconstruct- -ed of a front `and a rear substantially semispherical orcup-shaped part, (indicated at B and B', respectively.) The rear casingpart B is secured to the front face of the enlarged end of the arm A, asby means of screws b,

passing through the base of the part B into the arm. The casing ispreferablymade of thin sheet metal, and as the same is often sub- Themeeting open or flaring ends of the two casing parts BB areprovidcd withstraight annular overlapping securing rims or flanges d d, respectively,through which pass securing-screws (Z2, which detachably connect thecasing parts. The outer casing part B is provided centrally of its outerend with-a central v opening e.

Within the lcasing is arranged a tubular holder for the microphone ortransmitter proper. This tubular holder comprises branch tubes orpassages F F', connected at their outer ends to a screw-threaded ring f,which projects outwardly through the opening e in the casing part B andhaving their inner open ends turned toward each other and separated toprovide a space therebetween for the microphone. rIhe tubular holder issecured or held in place in the casing by means ofthe mouthpiece Gr,which is arranged outside oi' the casing and is provided with a neck g,having an internal screw-thread adapted to engage with theoutwardly-projecting screw-threaded ring of the tubular holder. As themouthpiece is made of thin sheet metal, it is not practical to make thescrew-thread directly in the metal thereof. The neck is thereforeenlarged to provide a seat g', in which a separate metal ring g2 isseated and secured, as by solder, the ring having the screw-thread cutinternally therein. The rear or inner end of the neck is formed into abead g3, which bears on the front casing part B and makes an attractivefinish. By screwing themouthpiece on the ring f the holder and themouthpiece areclamped-tightly'on the casing part B. The tubular holder(see particularly Figs. 2, 3, 4, and v5) is preferably madey up ofsubstantially C-shaped sideplates L h, the inner edges of which areconnected by a curved plate L andv the outer edges of which areconnected by outer curved plates if 7b3. The several plates are securedtogether in any suitable mannerfor instance, by solder-forming thebranch tubes or passages, the open outer ends of which are connectedwith the screw-threaded ring f, as by solder.

as to cut the entering sound-waves and not offer an obstruction to thesame. The joint between ,the front ends of the branch tubesv F F andtheringf is rounded off, so as not to leaveV any sharp angles orprojections which can obstruct the passage of the sound-waves. The rearends of the outer curved plates h2 and h3 are provided withrearwardly-extending securing earsor lianges if, and the rear ends ofthe C-shaped side plates /L are provided,

with laterally-projecting ears or flanges h5.

The microphone, which is represented at I,

branch tube of the holder, which openings expose the central portions ofthe transmitting-diaphragms K K, arranged adjacent to the inner faces ofthe plates J J, to the soundwaves. The construction of the microphoneproper forms no part of this application, and it is not believednecessary to describe the same herein, it being sufficient to state thatall ofY the working parts of the microphone are contained in and securedto the containing-frame between the plates J J and protected thereby.This containing-frame is arranged between the separated rear ends of thebranch tubes F F', and it, together with the parts of the microphone, isremovable as an entirety from the tubular mounting, for which purposethe containing-frame is detachably secured to the branch tubes by meansof screws la, passing through the ears or securing-flanges and h5.

The preferred manner of supporting the transmitting-diaphragms in thecontainingframe is illustrated in Figs. 1, 8, and 9 and is as follows: Lrepresents holding clips or springs for the transmitter-diaphragms ar-The inner curved. plate L is preferably wedge-shaped at its front end,so

ranged at opposite sides of each frame-plate J. Each holding clip orspring has-a central outwardly-projecting portion'l, which is securedtoa corresponding portion Z', projecting beyond the periphery of theadjacent frame-plate J, by a screw Z2, which passes through said parts,`and a spacing-sleeve Z3, placed between the holding-clip andframeplate. The opposite ends l* of the clips are of substantially .thesame curvature as theperiphery of the frame-plate and are bent ordeflected toward the same. The transmittingdiaphragms are held irmly bythe clips between the. same and the frame-plates. The holding-clips alsoform the electrical connections between the diaphragms and the'binding-posts M for the conducting-wires. The

binding-posts are Vsecured to the frame-platesby the screws Z2 for thediaphragm-holding clips.

The ,parts are 'assembled by inserting the microphone containing framebetween the inner ends of the branch tubes of the tubular holder andsecuring the same thereto by the screws le. The screw-threaded ringf ofthe holder is then passed through the opening e in the outer casing'partB and the mouthpiece screwed thereon to tightly clamp the same to the outer casing part. The casing parts B and B are secured together by thescrews d2,

passing through their overlapping ianges d al. In case any of the partsof the microphone are broken or become inoperative from any cause or itis desired for any purpose to inspect the microphone it is a matter ofvery little difficulty to separate the parts of the inr closing casing,remove the tubular holder, and

detach the containing-frame therefrom. rIhe entire containing-frame andparts contained thereby can then be replaced by another, or

the microphone can be repaired and the containing-frame againsecured inthe holder and the parts assembled, as above stated.

In Figs. 10 and 11' is shown a containing-frame for a slightly-dierentform of microphone. The containing-frame is similar in construction tothat already described, having the separated plates or disks N connectedby screws and posts, as stated, and it is similarly secured between theinner ends of the branched-tube holder; With the microphone used withthis containing-frame it is necessary to insulate the holding clips or'springs from the containing-frame. This is done by insulating-bushingsfn, surrounding the securing-screws n and insulating-washers n2 betweenthe sleeve n3 and frame-plate and between the latter and thebinding-post n4.

I claim as my invention- 1. The combination of a support, a casingsupported thereby, a microphone within said IOO IIS

casing, a tubular holder for said microphone tubular holder together andto said casing,-

substantially as set forth.

Q. The combination of a support, a casing supported thereby, amicrophone within said casing, a branched tubular holder located withinsaid casing and having separated inner ends between which saidmicrophone is supported, a mouthpiece outside of said casing, and ascrew threaded connection between said mouthpiece and said tubularholder, whereby said parts are attached together and detachably clampedon`said casing, substantially as set forth.

3. The combination of a branched tubular holder having separated-ends, amicrophone, and a containing-frame for the microphone having separatedplates on opposite sides of the microphone and arranged between theseparated ends of said tubular holder and detachably secured thereto,substantially as set forth.

4. The combination of a supporting-arm, a casing secured thereto andformed of separable parts one of which is provided with an opening, amicrophone within said casing, a tubular holder for said microphonelocated within said casing and having a part projecting through saidopening, and a mouthpiece outside of said casing and having ascrewthreaded engagement with said projecting part of said tubularholder, whereby the latter and said mouthpiece are connected togetherand clamped on said casing, substantially as set forth.

5. The combination with a transmitter-arm, of a casing secured theretoandA composed of two substantially cup-shaped parts, means fordetachably connecting said parts, a branched tubular holder arrapged insaid casing and having a screw threaded ring projecting through anopening in one of said casing parts,

a mouthpiece screwed on said projecting ring, i

inside of and adjacent to said plates and protected thereby, andspring-clips secured to said containing-frame and arranged between andbearing against said diaphragms to hold the same in place .between saidcover-plates, substantially as set forth.

7. The combination of a containing-frame having separated plates, amicrophone between said plates having diaphragms each located inside ofand adjacent to one of said frame-plates, and holding-clips secured tosaid frame-plates and extending between said diaphragms for holding thesame in said containing-frames, substantially as set forth.

8. The combination of a containing-frame comprising separated platesdetachably connected together, a microphone contained between saidplates and having a diaphragm, and means securing said diaphragm to oneof said frame-plates whereby when said plate is detached from the otherparts of the containingframe the diaphragm is carried by it,substantially as set forth.

Witness my hand this 16th day of January, 1902.

WALTER L. VILHELM.

Witnesses:

CHAs. W. PARKER, CLAUDIA M. BENTLEY.

